The present invention relates to an automatic bread baking machine for automatically baking a small amount of bread, mainly for home use.
A bread baking procedure starts with the preparation of dough by kneading the ingredients of bread, i.e. wheat flour, a yeast fungus and small amounts of butter and sugar, with water. The dough is primary-fermented, degassed, secondary-fermented, degassed and fermented for shaping, and thereafter baked. Usually, about three to four hours are needed for baking bread after starting the kneading of the ingredients. Accordingly, for example, if it is desired to complete baking at seven o'clock in the morning, then it is necessary to start kneading of the ingredients of bread at about 3 a.m. A conventional domestic kneader for kneading the ingredients of bread includes a rotary vane which is driven at the comparatively high speed of 400-800 rpm, and for example, in a container containing the ingredients, the kneading operation produces violent vibrations and loud noises. Accordingly, it is not desirable to operate such a noisy kneader early in the morning. While there have been proposed kneaders for business use that have a low speed rotary vane (e.g. 50-100 rpm), if such a low rotational speed is employed in domestic kneaders whose containers have a relatively small size, the tangential velocity of the vane would be small, resulting in less production of gluten. Thus, it has been conventional to employ a high rotational speed for domestic kneaders. There has been proposed a kneader having projections on the interior surface of the container for the purpose of increasing the kneading efficiency. With this type of kneader, however, since the dough is rotated by the rotary vane and hit against the projections to heighten the kneading effect, violent vibrations and loud noises are generated.
Furthermore, the conditions for kneading, fermentation and degassing of the dough vary under the influence of temperature or humidity; therefore, the conditions for making bread differ with season. With conventional bread baking machines, the kneading time, the temperature in the container and other conditions are adjusted by the baker in accordance with season, temperature and humidity prior to the kneading and the fermentation step. This adjustment cannot always be done satisfactorily and it is difficult to bake uniformly excellent bread at all times. In particular, as the ingredients of bread are kneaded, the dough temperature rises, and if the dough temperature is raised too high, excellent bread cannot be obtained.
In conventional bread baking machines for domestic use, a kneader, a fermenter and a baking oven are usually separate of one another, but in some of the conventional machines they are assembled together. In the latter type 8 machine, however, the dough produced by the kneader is manually transferred to the fermenter and the fermented dough is manually transferred to the oven. Further, control of the fermenter and the oven is also manual. That is, there has not been put to practical use an automatic bread baking machine which does not involve any manual operations until bread is baked after its ingredients are put in the machine.
What is disclosed in, for example, Japanese Utility Model Public Disclosure No. 10388/81, is a machine which starts the kneading operation immediately after the ingredients of bread are put in a container. Further, Japanese Utility Model Public Disclosures Nos. 45284/81, 68480/81 and 89384/81 disclose bread baking machines of the type in which the ingredients of bread are preset and the kneading operation is started at a predetermined time. But, these machines are complex in structure and have not been put to practical use.
It is an object of the present invention to provide an automatic bread baking machine which permits automatic baking of bread without involving any manual operations after the ingredients of bread are put in the machine.
Another object of the present invention is to provide an automatic bread baking machine which permits sufficient kneading of the ingredients of bread at a low rotating speed, and hence does not produce violent vibrations and loud noises.
Yet another object of the present invention is to provide an automatic bread baking machine which permits baking of excellent bread at all times without being affected by ambient temperature.